Many pedal cyclists suffer injuries or death in traffic accidents every year. One reason for this is that acceleration and deceleration of a cyclist is erratic when compared to motor powered vehicles as it is influenced by factors such as incline of the road, the gear being used and the level of fatigue of the cyclist. As it is very difficult to predict acceleration and deceleration of a cyclist, other road users try to pass them by with a wider berth than they would typically give other road users. However, where a cyclist decelerates suddenly without warning and is in the path of another road user, it is sometimes too late to react properly by the time the other road user has realized the cyclist is/has decelerated.